U.S. patent number 11,059,371 [Application Number 16/491,481] was granted by the patent office on 2021-07-13 for on-vehicle power supply device and vehicle having on-vehicle power supply device mounted thereon.
This patent grant is currently assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.. The grantee listed for this patent is Panasonic Intellectual Property Management Co., Ltd.. Invention is credited to Katsunori Atago, Takashi Higashide, Hisao Hiragi, Youichi Kageyama, Yugo Setsu, Kazuo Takenaka.
United States Patent |
11,059,371 |
Kageyama , et al. |
July 13, 2021 |
On-vehicle power supply device and vehicle having on-vehicle power
supply device mounted thereon
Abstract
An on-vehicle power supply device according to the present
disclosure includes an electricity storage, a charge circuit, a
discharge circuit, an input unit, an output unit and a controller.
When the controller decides that an emergency operation condition
is satisfied, the controllers causes the charge circuit to stop
charging power to the electricity storage, then sets an output
instruction voltage that is a target voltage value of an output of
the discharge circuit to a first voltage value, the controller
further causes the discharge circuit to discharge the power charged
in the electricity storage, and, when the power output from the
discharge circuit becomes higher than a power threshold, the
controller lowers an output instruction voltage from a first
voltage value to a second voltage value.
Inventors: |
Kageyama; Youichi (Fukushima,
JP), Atago; Katsunori (Fukushima, JP),
Takenaka; Kazuo (Fukushima, JP), Hiragi; Hisao
(Saitama, JP), Setsu; Yugo (Fukushima, JP),
Higashide; Takashi (Fukushima, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Panasonic Intellectual Property Management Co., Ltd. |
Osaka |
N/A |
JP |
|
|
Assignee: |
PANASONIC INTELLECTUAL PROPERTY
MANAGEMENT CO., LTD. (Osaka, JP)
|
Family
ID: |
1000005675359 |
Appl.
No.: |
16/491,481 |
Filed: |
March 16, 2018 |
PCT
Filed: |
March 16, 2018 |
PCT No.: |
PCT/JP2018/010497 |
371(c)(1),(2),(4) Date: |
September 05, 2019 |
PCT
Pub. No.: |
WO2018/180606 |
PCT
Pub. Date: |
October 04, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200016981 A1 |
Jan 16, 2020 |
|
Foreign Application Priority Data
|
|
|
|
|
Mar 27, 2017 [JP] |
|
|
JP2017-061044 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60L
3/0046 (20130101); B60L 50/60 (20190201); B60L
53/62 (20190201); B60R 21/013 (20130101) |
Current International
Class: |
B60L
3/00 (20190101); B60R 21/013 (20060101); B60L
50/60 (20190101); B60L 53/62 (20190101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
International Search Report of PCT application No.
PCT/JP2018/010497 dated Jun. 19, 2018. cited by applicant.
|
Primary Examiner: Nguyen; Nha T
Attorney, Agent or Firm: McDermott Will and Emery LLP
Claims
The invention claimed is:
1. An on-vehicle power supply device comprising: an electricity
storage; a charge circuit that is provided on a charging route of
the electricity storage, and charges the electricity storage with
power; a discharge circuit that is provided on an output route of
the electricity storage, and discharges the power of the
electricity storage; an input unit that is connected with the
charge circuit; an output unit that is connected with the discharge
circuit; and a controller that detects an input voltage of the
input unit, an output current of the output unit, and an output
voltage of the output unit, and controls the charge circuit and the
discharge circuit, wherein when the controller decides that an
emergency operation condition is satisfied, the controllers causes
the charge circuit to stop charging the power to the electricity
storage, then sets an output instruction voltage that is a target
voltage value of an output of the discharge circuit to a first
voltage value, the controller further causes the discharge circuit
to discharge the power charged in the electricity storage, and,
when the power output from the discharge circuit becomes higher
than a power threshold, the controller lowers the output
instruction voltage from the first voltage value to a second
voltage value.
2. The on-vehicle power supply device according to claim 1,
wherein, when the controller detects that the input voltage has
become lower than an input lower limit voltage, the emergency
operation condition is satisfied.
3. The on-vehicle power supply device according to claim 1, further
comprising a receiver that is connected with the controller and
receives a collision signal, wherein, when the receiver receives
the collision signal, the emergency operation condition is
satisfied.
4. The on-vehicle power supply device according to claim 1,
wherein, when the power output from the discharge circuit becomes
higher than the power threshold and then becomes lower than the
power threshold again, the output instruction voltage is increased
from the second voltage value to the first voltage value.
5. The on-vehicle power supply device according to claim 1, wherein
the power output from the discharge circuit and the power threshold
are compared by using a current value.
6. The on-vehicle power supply device according to claim 1,
wherein, when lowering the output instruction voltage from the
first voltage value to the second voltage value, the controller
lowers the output instruction voltage from the first voltage value
to the second voltage value continuously or stepwise.
7. The on-vehicle power supply device according to claim 1, further
comprising a residual detector that detects a residual electricity
storage amount of the electricity storage, wherein the power
threshold is determined based on the residual electricity storage
amount of the electricity storage detected by the residual
detector.
8. An on-vehicle power supply device comprising: an electricity
storage; a charge circuit that is provided on a charging route of
the electricity storage, and charges the electricity storage with
power; a discharge circuit that is provided on an output route of
the electricity storage, and discharges the power of the
electricity storage; an input unit that is connected with the
charge circuit; an output unit that is connected with the discharge
circuit; and a controller that detects an input voltage of the
input unit, an output current of the output unit, and an output
voltage of the output unit, and controls the charge circuit and the
discharge circuit, wherein when the controller decides that an
emergency operation condition is satisfied, the charge circuit
stops charging of the electricity storage, then the discharge
circuit discharges the power at a first voltage value, the
controller further causes the discharge circuit to discharge the
power charged in the electricity storage, and, when the power
output from the discharge circuit becomes higher than a power
threshold, the discharge circuit discharges the power at a second
voltage value smaller than the first voltage value.
9. A vehicle comprising: the on-vehicle power supply device
according to claim 1; a vehicle body on which the on-vehicle power
supply device is mounted; and a vehicle battery that is mounted on
the vehicle body and supplies power to the on-vehicle power supply
device.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. national stage application of the PCT
International Application No. PCT/JP2018/010497 filed on Mar. 16,
2018, which claims the benefit of foreign priority of Japanese
patent application No. 2017-061044 filed on Mar. 27, 2017, the
contents all of which are incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates to an on-vehicle power supply device
and an on-vehicle power supply device vehicle.
BACKGROUND ART
A conventional on-vehicle power supply device will be described
below with reference to the drawings. FIG. 9 is a circuit block
diagram illustrating a configuration of the conventional on-vehicle
power supply device, and output unit 30 of on-vehicle power supply
device 1 is connected with load 2. On-vehicle power supply device 1
includes electricity storage element 3, auxiliary electricity
storage element 4 and switch unit 5. Electricity storage element 3
is connected with output unit 30 via switch unit 5, and auxiliary
electricity storage element 4 is connected with an output of switch
unit 5. That is, auxiliary electricity storage element 4 is
connected with output unit 30. When the voltage of electricity
storage element 3 is normal, switch unit 5 causes electricity
storage element 3 to supply power to load 2. Simultaneously, switch
unit 5 operates such that electricity storage element 3 charges
auxiliary electricity storage element 4.
On the other hand, when the voltage of electricity storage element
3 lowers, switch unit 5 discharges power of auxiliary electricity
storage element 4 and superimposes the voltage of auxiliary
electricity storage element 4 on the voltage of electricity storage
element 3. Both of electricity storage element 3 and auxiliary
electricity storage element 4 supply power to load 2. According to
this configuration, even when the voltage of electricity storage
element 3 lowers, on-vehicle power supply device 1 can supply power
to load 2 at a stable voltage.
It should be noted that, for example, PTL 1 is known as a prior art
document containing information related to this application.
CITATION LIST
Patent Literature
PTL 1: PCT International Publication No. 2013/125170
SUMMARY OF THE INVENTION
An on-vehicle power supply device according to one aspect of the
present disclosure includes: an electricity storage; a charge
circuit that is provided on a charging route of the electricity
storage, and charges the electricity storage with power; a
discharge circuit that is provided on an output route of the
electricity storage, and discharges the power of the electricity
storage; an input unit that is connected with the charge circuit;
an output unit that is connected with the discharge circuit; and a
controller that detects an input voltage of the input unit, an
output current of the output unit, and an output voltage of the
output unit, and controls the charge circuit and the discharge
circuit, and, when the controller decides that an emergency
operation condition is satisfied, the controllers causes the charge
circuit to stop charging the power to the electricity storage, then
sets an output instruction voltage that is a target voltage value
of an output of the discharge circuit to a first voltage value, the
controller further causes the discharge circuit to discharge the
power charged in the electricity storage, and, when the power
output from the discharge circuit becomes higher than a power
threshold, the controller lowers the output instruction voltage
from the first voltage value to a second voltage value.
Furthermore, a vehicle according to the present disclosure
includes: the on-vehicle power supply device according to the above
one aspect; a vehicle body on which the on-vehicle power supply
device is mounted; and a vehicle battery that is mounted on the
vehicle body and supplies power to the on-vehicle power supply
device.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a circuit block diagram illustrating a configuration of
an on-vehicle power supply device according to a first exemplary
embodiment of the present disclosure.
FIG. 2 is a circuit block diagram illustrating a configuration of a
vehicle on which the on-vehicle power supply device according to
the first exemplary embodiment of the present disclosure is
mounted.
FIG. 3A is a flowchart for explaining an operation of the
on-vehicle power supply device according to the first exemplary
embodiment of the present disclosure.
FIG. 3B is a flowchart for explaining an operation of an on-vehicle
power supply device according to a second exemplary embodiment of
the present disclosure.
FIG. 3C is a flowchart for explaining an operation of an on-vehicle
power supply device according to an exemplary embodiment of the
present disclosure.
FIG. 3D is a flowchart for explaining the operation of the
on-vehicle power supply device according to the exemplary
embodiment of the present disclosure.
FIG. 4 is a timing chart for explaining the operation of the
on-vehicle power supply device according to the first exemplary
embodiment of the present disclosure.
FIG. 5 is a block diagram illustrating a configuration of a vehicle
on which the on-vehicle power supply device according to the second
exemplary embodiment of the present disclosure is mounted.
FIG. 6 is a timing chart for explaining the operation of the
on-vehicle power supply device according to the second exemplary
embodiment of the present disclosure.
FIG. 7 is a flowchart illustrating the operation of the on-vehicle
power supply device according to the third exemplary embodiment of
the present disclosure.
FIG. 8 is a block diagram illustrating a configuration of a vehicle
on which the on-vehicle power supply device according to a fourth
exemplary embodiment of the present disclosure is mounted.
FIG. 9 is a circuit block diagram illustrating a conventional
on-vehicle power supply device.
DESCRIPTION OF EMBODIMENTS
On-vehicle power supply device 1 described with reference to FIG. 9
needs to include auxiliary electricity storage element 4 that makes
up for a decrease when the voltage of electricity storage element 3
decreases. Hence, a number of elements that make up on-vehicle
power supply device 1 increases. As a result, on-vehicle power
supply device 1 becomes large.
On-vehicle power supply device 6 according to the present
disclosure described below can stably operate, and realize
miniaturization.
First Exemplary Embodiment
The first exemplary embodiment of the present disclosure will be
described below with reference to the drawings.
FIG. 1 is a circuit block diagram illustrating a configuration of
on-vehicle power supply device 6 according to the first exemplary
embodiment of the present disclosure. On-vehicle power supply
device 6 includes electricity storage 7, charge circuit 8,
discharge circuit 9, input unit 10, output unit 11 and controller
12.
Charge circuit 8 is provided on a charging route of electricity
storage 7, and can charge electricity storage 7 with power.
Discharge circuit 9 is provided on an output route of electricity
storage 7, and discharges the power of electricity storage 7. Input
unit 10 is connected with charge circuit 8, and output unit 11 is
connected with discharge circuit 9. Controller 12 detects an input
voltage of input unit 10, an output current of output unit 11 and
an output voltage of output unit 11, and controls operations of
charge circuit 8 and discharge circuit 9.
FIG. 1 illustrates power supply routes as bold lines, and signal
transmission routes as thin lines. For example, the power supply
route which connects input unit 10 and charge circuit 8 is
illustrated as the bold line, and the signal transmission route
which connects input unit 10 and controller 12 is illustrated as a
thin line. However, whether power transmitted through the power
supply routes or the signal transmission routes is high or low is
just an indication, and each of the bold lines and the thin lines
is electrically connected likewise.
When controller 12 detects that an input voltage of input unit 10
is more than or equal to an input lower limit voltage, controller
12 decides that normal operation conditions are satisfied.
Furthermore, controller 12 controls charge circuit 8 such that
charge circuit 8 continuously or intermittently charges electricity
storage 7 in order that output unit 11 reaches a predetermined
electricity storage voltage. A state where the input voltage is
more than or equal to the input lower limit voltage will be
referred to as a "normal mode" below.
On the other hand, when controller 12 detects that the input
voltage is lower than the input lower limit voltage, controller 12
decides that emergency operation conditions are satisfied.
Furthermore, controller 12 performs control to cause charge circuit
8 to stop charging electricity storage 7, and then discharge power
from electricity storage 7 to discharge circuit 9. In this case,
controller 12 instructs an output instruction voltage which is a
target voltage value of an output of discharge circuit 9 to
discharge circuit 9, and starts discharging power from electricity
storage 7 to discharge circuit 9. The output instruction voltage in
this case is a "first voltage value". A state where the input
voltage is lower than the input lower limit voltage will be
referred to as an "emergency power supply mode" below.
Subsequently, when output power of the output current and the
output voltage is more than or equal to a power threshold,
controller 12 instructs discharge circuit 9 to lower the output
instruction voltage from the first voltage value to the second
voltage value. Details of a change in the voltage will be described
below with reference to FIG. 4.
As described above, when large output power is necessary in the
emergency power supply mode, on-vehicle power supply device 6
lowers the output instruction voltage from the first voltage value
to the second voltage value. According to this configuration,
temporary pulsation of a voltage which occurs as the output power
reaches a supply limit, in other words, temporary pulsation of a
voltage which occurs due to an influence from load 13 connected
with output unit 11 is suppressed. Consequently, a fluctuation of a
high output voltage is alleviated. On-vehicle power supply device 6
can output a stable voltage without additionally providing an
auxiliary electricity storage element (e.g., electricity storage
element 3 illustrated in FIG. 9). As a result, on-vehicle power
supply device 6 can stably operate, and realize miniaturization at
the same time.
Next, details of a configuration and an operation of on-vehicle
power supply device 6 will be described with reference to the
drawings. FIG. 2 is a block diagram illustrating a configuration of
vehicle 14 on which on-vehicle power supply device 6 according to
the first exemplary embodiment of the present disclosure is
mounted. FIG. 3A is a flowchart for explaining the operation of
on-vehicle power supply device 6 according to the first exemplary
embodiment of the present disclosure, and FIG. 4 is a timing chart
for explaining the operation of on-vehicle power supply device 6
according to the first exemplary embodiment of the present
disclosure.
As illustrated in FIG. 2, on-vehicle power supply device 6 is
disposed in vehicle 15 which makes up vehicle 14. Input unit 10 is
connected with vehicle battery 17 via switch 16. Furthermore,
output unit 11 is connected with load 13. Furthermore, vehicle
battery 17 is connected with load 13 via transmission line 18. In
addition, on-vehicle power supply device 6 has already been
described with reference to FIG. 1, and therefore description of
on-vehicle power supply device 6 will be omitted.
When a passenger gets on vehicle 14 and turns on or off an
activation switch (not illustrated) for activating vehicle 14,
switch 16 is turned on or off. Furthermore, when the passenger
switches switch 16 from off to on, vehicle 14 is activated, and
switch 16 enters a connection state. Furthermore, controller 12 of
on-vehicle power supply device 6 is also activated. The above
corresponds to step Ain the flowchart in FIG. 3A.
Next, controller 12 is connected with input unit 10, and detects
the input voltage of input unit 10 at all times. In addition, by
connecting controller 12 with charge circuit 8 and detecting the
input voltage of charge circuit 8, the input voltage of input unit
10 may be detected. That controller 12 detects the input voltage of
input unit 10 means that controller 12 detects the voltage of
vehicle battery 17. Furthermore, when controller 12 detects a
voltage of vehicle battery 17, controller 12 activates charge
circuit 8. Furthermore, charge circuit 8 continuously or
intermittently charges electricity storage 7 to a predetermined
electricity storage voltage. The above corresponds to step B and
step C in the flowchart in FIG. 3A.
In addition, although the present exemplary embodiment has
described charge circuit 8 and input unit 10 as individual
elements, charge circuit 8 may include input unit 10.
In addition, according to the present exemplary embodiment,
controller 12 detects the voltage of vehicle battery 17, and then
charge circuit 8 charges electricity storage 7. However, an order
of these operations may be reverse.
Furthermore, if vehicle battery 17 is in an anomaly state during
activation of vehicle 14, vehicle 14 is not normally activated.
Hence, when vehicle 14 is not normally activated, on-vehicle power
supply device 6 is not activated, either. The operation of
on-vehicle power supply device 6 described below is an operation
performed when vehicle battery 17 is in a normal state at a point
of time at which vehicle 14 is activated. Furthermore, the
operation of on-vehicle power supply device 6 described below is
performed in a state where, after vehicle 14 is normally activated,
vehicle 14 is being normally driven or can be driven.
Next, step D will be described. Controller 12 compares the input
lower limit voltage and the input voltage by using the input
voltage detected in step B. A value which cannot be taken while
vehicle 14 normally operates is set to the input lower limit
voltage. The input lower limit voltage may be set assuming a state
where, for example, vehicle 14 causes a collision accident, and
vehicle battery 17 becomes defective. In other words, the input
lower limit voltage can be set to a value close to a low value such
as 0 V to several V at which control unit 19 which controls entire
vehicle 14 and load 13 cannot operate.
When the input voltage takes a value larger than the input lower
limit voltage, controller 12 decides that vehicle 14 or vehicle
battery 17 is in the normal state without encountering an accident,
and the operation returns to step B. When controller 12 detects the
input voltage and compares and decides the input voltage and the
input lower limit voltage at all times while vehicle 14 is in an
activated state. The above corresponds to "No" in step D in the
flowchart in FIG. 3A.
In addition, while controller 12 decides that vehicle 14 and
vehicle battery 17 are normal, discharge circuit 9 does not
basically operate load 13. Discharge circuit 9 is connected with
controller 12, and controller 12 controls an operation of discharge
circuit 9. There is a case where, while controller 12 decides that
vehicle 14 and vehicle battery 17 are normal, discharge circuit 9
operates to temporarily adjust an electricity storage amount of
electricity storage 7. In this case, discharge circuit 9 only
outputs weak power compared to a capacity of power which
electricity storage 7 can store, and this weak power does not
influence the operation of load 13. Furthermore, when controller 12
decides that vehicle 14 and vehicle battery 17 are normal, power is
supplied to control unit 19 and load 13 from vehicle battery 17 via
transmission line 18. The present exemplary embodiment makes
connection which enables power supply to load 13 from vehicle
battery 17 at all times. However, load 13 actually includes a
plurality of various loads. Hence, a load switch (not illustrated)
which interlocks with switch 16 may be provided between vehicle
battery 17 and load 13.
Repetition of step B, step C and step D in FIG. 3A described herein
is a normal mode, and is an operation in a case where vehicle 14
and vehicle battery 17 are normal as described above.
Next, an operation in a case where the processing proceeds from
step D to step E will be described. A case where the processing
proceeds to step E will be described as an "emergency power supply
mode" in the present exemplary embodiment.
Controller 12 compares the input lower limit voltage and the input
voltage by using the input voltage detected in step B. When the
input voltage takes a value less than or equal to the input lower
limit voltage, controller 12 decides that vehicle 14 and vehicle
battery 17 encounter an accident and are in an anomaly state
("emergency power supply mode"). This corresponds to "Yes" in step
D in the flowchart of FIG. 3A.
When controller 12 decides that the input voltage takes the value
less than or equal to the input lower limit voltage even though
switch 16 is in a connected state (even though vehicle 14 is in an
activated state), and controller 12 performs following control as
the emergency power supply mode.
First, when controller 12 decides in step D that the input voltage
takes the value less than or equal to the input lower limit
voltage, controller 12 causes charge circuit 8 to stop charging
electricity storage 7. Subsequently, controller 12 places discharge
circuit 9 in a dischargeable state, and controls discharge circuit
9 to perform a discharging operation to drive load 13. When
controller 12 decides that the input voltage takes the value less
than or equal to the input lower limit voltage, discharge circuit 9
immediately performs the discharging operation.
In addition, although the discharging operation of discharge
circuit 9 is started when it is decided that the input voltage
takes the value less than or equal to the input lower limit voltage
in the present exemplary embodiment, the discharging operation of
discharge circuit 9 may be performed in response to that controller
12 receives from an outside a signal for causing discharge circuit
9 to operate as indicated in step D in FIG. 3B. As one example of a
received signal from the outside in FIG. 3B, a collision signal is
used.
In this regard, a target voltage value of the voltage which is
output by discharge circuit 9 to drive load 13 will be referred to
as an "output instruction voltage". Controller 12 sets the output
instruction voltage to the first voltage value. Furthermore,
discharge circuit 9 discharges power stored in electricity storage
7 such that the output instruction voltage is the first voltage
value. Although not illustrated in FIGS. 1 and 2, power for
operating controller 12 is supplied from electricity storage 7 or
discharge circuit 9 in the emergency power supply mode.
Furthermore, when controller 12 decides that the input voltage
takes the value less than or equal to the input lower limit voltage
to maintain the functions of controller 12 and control unit 19,
discharge circuit 9 supplies a predetermined voltage to controller
12 and control unit 19 with small power compared to power
immediately supplied to load 13. The above corresponds to step E in
the flowchart in FIG. 3A.
Next, controller 12 detects the output voltage and the output
current of discharge circuit 9. In addition, controller 12 may
detect the output voltage and the output current of output unit 11
instead of an output of discharge circuit 9. In other words,
controller 12 detects power (referred to as "output power" below)
supplied to load 13. In this regard, the power supplied to load 13
may be calculated by controller 12 by a product of the output
voltage and the output current of discharge circuit 9 (or a product
of the output voltage and the output current of output unit 11).
The above corresponds to step F in the flowchart in FIG. 3A. In
this regard, although discharge circuit 9 and output unit 11 have
been described as different components, discharge circuit 9 may
include output unit 11.
Next, controller 12 compares the power threshold and the output
power by using the output voltage and the output current detected
in step F. The power threshold is determined based on a maximum
electricity storage amount of electricity storage 7, and a
discharge time taken to supply power from discharge circuit 9 to
load 13. In addition, a power threshold determining method is not
limited to this. The above corresponds to step F in the flowchart
in FIG. 3A. When the output power is less than or equal to the
power threshold in step G, controller 12 instructs discharge
circuit 9 to continuously operate by using the output instruction
voltage as the first voltage value ("No" in step G).
On the other hand, when the output power is higher than the power
threshold, controller 12 instructs discharge circuit 9 to lower the
output instruction voltage from the first voltage value to the
second voltage value. This corresponds to G and step H in the
flowchart in FIG. 3A.
Hereinafter, a case where controller 12 instructs discharge circuit
9 to maintain output instruction voltage V1 at the first voltage
value, and a case where output instruction voltage V3 is changed
from the first voltage value to output voltage V2 will be compared
with reference to FIG. 4.
FIG. 4 illustrates a change of output voltage V2 in a case where
controller 12 instructs discharge circuit 9 to maintain output
instruction voltage V1 at the first voltage value. Furthermore,
FIG. 4 illustrates a change of output voltage V4 in a case where
controller 12 instructs discharge circuit 9 to lower output
instruction voltage V3 from the first voltage value to the second
voltage value. Furthermore, FIG. 4 illustrates a change of output
power W1 from output unit 11, too.
Hereinafter, an example where load 13 is an electric motor will be
described. As indicated by W1 in FIG. 4, discharge circuit 9 starts
supplying power to load 13 at a timing of t0 to activate load 13
(electric motor). At a timing from t0 to t2, the operation of load
13 is not in a stationary state. That is, between t0 and t2, i.e.,
until the electric motor starts rotating at a constant speed after
receiving a supply of power, a large current temporarily flows to
load 13. Furthermore, there is a limit of power that can be
supplied to load 13 by electricity storage 7 and discharge circuit
9.
Hence, when control is performed to instruct discharge circuit 9 to
maintain output instruction voltage V1 at the first voltage value
as illustrated in FIG. 4, and a large current flows to
instantaneously supply high power to load 13, if the value of the
output current of discharge circuit 9 becomes too large, discharge
circuit 9 continues operating in a state where discharge power is
maintained. Hence, to maintain the discharge power, output voltage
V2 of discharge circuit 9 temporarily lowers substantially in some
cases. That is, output voltage V2 output from discharge circuit 9
and detected by output unit 11, and output instruction voltage V1
instructed to discharge circuit 9 by controller 12 take different
values, and output voltage V2 becomes lower than output instruction
voltage V1.
A decrease in output voltage V2 of discharge circuit 9 is a
temporary phenomenon. Even when output power W1 temporarily
increases, output power W1 decreases in the end, and, as output
power W1 decreases, output voltage V2 returns to match with the
first voltage value.
However, in the emergency power supply mode that on-vehicle power
supply device 6 is activated, discharge circuit 9 needs to supply a
stable voltage to control unit 19 and controller 12 in some cases.
Hence, the output voltage of discharge circuit 9 in the emergency
power supply mode needs to maintain a higher voltage at all times
than control unit drive limit voltage VLo (referred to as limit
voltage VLo below). When controller 12 controls discharge circuit 9
to maintain output instruction voltage V1 at the first voltage
value irrespective of such a restriction, it is likely that output
voltage V2 of discharge circuit 9 temporarily lowers substantially
to maintain the discharge power, and output voltage V2 lowers to a
value lower than limit voltage VLo.
Hereinafter, a case where, at t1 which is a timing at which the
output power becomes larger than power threshold Wt, controller 12
performs control to cause discharge circuit 9 to lower output
instruction voltage V3 from the first voltage value to the second
voltage value will be described. In this case, too, a large current
flows from output unit 11 to supply high power to load 13.
Furthermore, if the value of the output current of discharge
circuit 9 becomes too large, discharge circuit 9 continues
operating in a state where discharge power is maintained. Hence, to
maintain discharge power, output voltage V4 of discharge circuit 9
is concerned to temporarily lower. However, output instruction
voltage V3 is lowered to the second voltage value, and therefore a
permitted amount of the output current in discharge circuit 9
becomes large. Hence, even when a large current instantaneously
flows to load 13, a decrease amount of output voltage V4 of
discharge circuit 9 caused by the large current is substantially
suppressed. Consequently, output voltage V4 of discharge circuit 9
easily maintains a higher voltage than limit voltage VLo. As a
result, even in the emergency power supply mode that on-vehicle
power supply device 6 is activated, discharge circuit 9 can supply
a stable voltage to control unit 19 and controller 12. Naturally,
the second voltage value is a higher voltage value than limit
voltage VLo.
In a timing chart in FIG. 4, a region in which the output voltage
of discharge circuit 9 temporarily lowers substantially due to
control for maintaining output instruction voltage V1 of discharge
circuit 9 at the first voltage value is indicated by hatching
output voltage V2. A region in which output voltage V4 of discharge
circuit 9 temporarily lowers substantially due to control for
lowering output instruction voltage V3 of discharge circuit 9 from
the first voltage value to the second voltage value is indicated by
hatching output voltage V4. These hatched areas substantially
correspond to an insufficient power amount of output power W1 in
discharge circuit 9. Hence, the area of the hatched region
indicating output voltage V2 which changes according to load 13,
and the area of the hatched region indicating output voltage V4
which is set by changing standards of output instruction voltage V3
are matched substantially. In other words, a value obtained by
integrating the insufficient voltage, and a value obtained by
integrating a value obtained by lowering the standards of the
output instruction voltage may be matched substantially.
Consequently, even when the large current instantaneously flows to
load 13, it is possible to substantially prevent a decrease in
output voltage V4 of discharge circuit 9 caused by the large
current. Alternatively, even when the large current instantaneously
flows to load 13, it is possible to prevent output voltage V4 of
discharge circuit 9 from lowering to less than or equal to the
second voltage value. The timing chart in FIG. 4 illustrates the
second voltage value as a fixed value, yet is influenced by load 13
in some cases and therefore pulsates in some cases.
As described above, controller 12 performs control according to the
timing chart in FIG. 4 in step G and step H in the flowchart in
FIG. 3A, so that on-vehicle power supply device 6 can stably
operate. That is, an auxiliary electricity storage element (e.g.,
auxiliary electricity storage element 4 in FIG. 9) is not provided
to electricity storage 7, and electricity storage 7 and discharge
circuit 9 output stable output voltage V4. Hence, on-vehicle power
supply device 6 can be miniaturized.
The above description has described an aspect of an operation
related to such an instruction from controller 12 to discharge
circuit 9 that controller 12 lowers output instruction voltage V3
from the first voltage value to the second voltage value. By
contrast with this, even if an aspect of the operation of discharge
circuit 9 will be described, an operation order is the same.
It has been stated that, when, for example, output power W1 becomes
larger than power threshold Wt in the emergency power supply mode
as described above, "controller 12 lowers output instruction
voltage V3 from the first voltage value to the second voltage
value". However, these control and operation may not be performed.
For example, it may be described that "control of controller 12
lowers output voltage V4 of discharge circuit 9 from the first
voltage to the second voltage". Regarding replacement of
description related to the control and the operation described
herein, the same operation and the same control are applicable.
Furthermore, it has been stated that "controller 12 makes the
output instruction voltage the first voltage value". However, this
may be replaced to read that "controller 12 performs control to
output the first voltage value to discharge circuit 9". In still
another example, it has been described that "controller 12 makes
output instruction voltage V3 the second voltage value". However,
this description may be replaced to read that "controller 12 causes
discharge circuit 9 to output the second voltage value".
Furthermore, FIG. 4 illustrates that, when output instruction
voltage V3 lowers to the second voltage value in the emergency
power supply mode, output voltage V4 shows a waveform similar to
the output instruction voltage for ease of description. However,
output voltage V4 may fluctuate a little in a period from t1 to t3.
Output voltage V4 maintains a higher voltage than limit voltage VLo
in the period from t1 to t3.
In this regard, operations in step I and step J illustrated in the
flowchart in FIG. 3A may be performed. When load 13 is the electric
motor as described above, a trajectory of a fluctuation of output
power W1 substantially corresponds to a trajectory of a torque
fluctuation of the electric motor which is load 13. Furthermore,
the trajectory of output power W1 passes a maximum value and starts
lowering as the time passes, and becomes lower than power threshold
Wt at a timing of t2. As described below, load 13 becomes close to
a stationary operation state at a timing of t3 after the timing of
t2, then the torque further lowers, and output power W1 becomes
lower than power threshold Wt at the timing of t3.
Output power W1 lowers when the operation (mainly rotation) of the
electric motor which is load 13 enters the stationary state or
becomes close to the stationary state. After the operation of load
13 enters the stationary state, large output power is not
requested. Hence, at a timing at which it is possible to regard
that load 13 enters the stationary state, output instruction
voltage V3 to discharge circuit 9 may be returned from the second
voltage value to the first voltage value. Consequently, output
voltage V4 from discharge circuit 9 becomes high at all times with
a margin with respect to limit voltage VLo. Consequently, discharge
circuit 9 can stably supply a drive voltage to control unit 19 and
controller 12.
The timing at which output instruction voltage V3 to discharge
circuit 9 is returned from the second voltage value to the first
voltage value may come after t2 of a timing at which output power
W1 becomes smaller again than power threshold Wt used before. The
timing at which output instruction voltage V3 to discharge circuit
9 is returned from the second voltage value to the first voltage
value may be t3 which passes a desired period from the timing of
t2. In the example illustrated in FIG. 4, output instruction
voltage V3 to discharge circuit 9 is returned from the second
voltage value to the first voltage value at the timing of t3. The
above corresponds to step I and step J in the flowchart in FIG.
3A.
As described above, controller 12 returns output instruction
voltage V3 from the second voltage value to the first voltage value
in this description. That is, the operation has been described from
the aspect related to the instruction of controller 12. By contrast
with this, the operation may be described from the aspect related
to the operation of discharge circuit 9. The control and the
operation described to read that "controller 12 returns the output
instruction voltage from the second voltage value to the first
voltage value" may be replaced with that "the output voltage of
discharge circuit 9 returns from the second voltage to the first
voltage under control of controller 12".
In the timing chart in FIG. 4, the operation in the stationary
state of load 13 continues by a timing of t4. Furthermore, at the
timing of t4, the operation of the electric motor which is load 13
reaches a limit of an operation range. In other words, when the
electric motor reaches a rotation limit from a state where the
electric motor is rotating, a large current flows again to load 13,
and large power is supplied. At t4 which is this timing or
subsequent to t4, the main operation of on-vehicle power supply
device 6 has been finished. Hence, after the timing of t4, output
instruction voltage V3 does not need to be changed to other
standards.
On-vehicle power supply device 6 according to the present exemplary
embodiment can more accurately decide whether or not the anomaly
state of vehicle 14 occurs. As a result, on-vehicle power supply
device 6 can operate in the emergency power supply mode at a
necessary timing.
Second Exemplary Embodiment
Next, the second exemplary embodiment will be described with
reference to FIGS. 3B, 5 and 6.
FIG. 5 is a block diagram illustrating a configuration of vehicle
14 on which on-vehicle power supply device 6 according to the
second exemplary embodiment is mounted. In addition, the same
components between a configuration of vehicle 14 illustrated in
FIG. 2 and the configuration of vehicle 14 illustrated in FIG. 5
will be assigned the same reference signs, and description of the
components will be omitted.
FIG. 3B is a flowchart for explaining an operation of an on-vehicle
power supply device according to the second exemplary embodiment. A
step different between a flowchart illustrated in FIG. 3A and the
flowchart illustrated in FIG. 3B is only step D.
As illustrated in FIG. 5, on-vehicle power supply device 6 is
provided with collision signal receiver 20 connected with
controller 12. Controller 12 detects an input voltage of input unit
10 at all times. In addition, controller 12 may detect the input
voltage from charge circuit 8. Furthermore, when controller 12
detects (1) that the input voltage has become lower than an input
lower limit voltage, (2) detects reception of a collision signal
via collision signal receiver 20, and detects at least one of (1)
and (2), in step D, the processing proceeds to "YES", and
on-vehicle power supply device 6 operates in an emergency power
supply mode similarly to the first exemplary embodiment (step E to
step H). Furthermore, similarly to the first exemplary embodiment,
according to the second exemplary embodiment, step I and step J may
be performed.
In addition, in the present exemplary embodiment, too, controller
12 receives power for an operation from electricity storage 7 or
discharge circuit 9 in the emergency power supply mode although not
illustrated in FIG. 5.
The emergency power supply mode of on-vehicle power supply device 6
is the same as that of above-described first exemplary embodiment.
Controller 12 causes charge circuit 8 to stop charging electricity
storage 7, makes an output instruction voltage to discharge circuit
9 the first voltage value (step E), and causes discharge circuit 9
to start discharging power of electricity storage 7. Furthermore,
when output power W1 becomes larger than power threshold Wt,
controller 12 lowers the output instruction voltage to discharge
circuit 9 from the first voltage value to the second voltage value
(step H).
Similarly to the first exemplary embodiment, on-vehicle power
supply device 6 according to the present exemplary embodiment can
more accurately decide whether or not the anomaly state of vehicle
14 occurs. As a result, on-vehicle power supply device 6 can
operate in the emergency power supply mode at a necessary
timing.
As illustrated in FIG. 5, collision signal receiver 20 is connected
with collision detector 21 disposed in vehicle body 15. Therefore,
when vehicle 14 encounters an accident, a collision signal is
transmitted from collision detector 21 to controller 12 via
collision signal receiver 20. In addition, although collision
signal receiver 20 and controller 12 indicate individual components
for ease of description, collision signal receiver 20 may be
included in controller 12.
The present exemplary embodiment does not describe a normal mode of
on-vehicle power supply device 6 in particular. However, when
controller 12 detects that the input voltage is higher than the
input lower limit voltage and controller 12 does not detect
reception of the collision signal via collision signal receiver 20,
on-vehicle power supply device 6 operates in the normal mode.
In addition, in a case where on-vehicle power supply device 6 is
caused to operate in the emergency power supply mode in the second
exemplary embodiment, too, similarly to the first exemplary
embodiment described with reference to FIG. 4, when output power W1
becomes higher than power threshold Wt (step G), controller 12
causes discharge circuit 9 to lower output instruction voltage V3
from the first voltage value to the second voltage value.
As indicated in a timing chart indicating an operation of the
on-vehicle power supply device in FIG. 6, a timing at which the
output instruction voltage to discharge circuit 9 is lowered from
the first voltage value to the second voltage value is decided by
comparing the output power and the power threshold as indicated in
step G in FIGS. 3A and 3B. However, as indicated in step G in FIGS.
3C and 3D, the timing may be decided by comparing output current I1
and current threshold It. In other words, all exemplary embodiments
of the present disclosure including a third exemplary embodiment
described below, the output current may be used for the output
power, and the current threshold may be used for the power
threshold.
Similarly to above FIG. 4, it will be assumed and stated that load
13 illustrated in FIG. 6 is an electric motor. In this case, it is
assumed that discharge circuit 9 starts supplying power to load 13
at a timing of t0 to activate load 13. The current starts flowing
to load 13 at the timing of t0. Between t0 and t2 and before the
operation of load 13 enters a stationary state (the electric motor
receives a supply of power and then starts rotating at a constant
speed), a large current (indicated as output current I1 in FIG. 6)
temporarily flows to load 13. However, the output voltage does not
start lowering at the timing of t0.
In other words, output voltage V4 starts lowering when power which
can be supplied from electricity storage 7 and discharge circuit 9
to load 13 reaches a limit. That is, output voltage V4 does not
immediately start lowering when output current I1 flows, but starts
at a timing of t1 which is a timing at which output current I1 is
more than or equal to current threshold It. Consequently,
controller 12 can accurately decide whether or not to cause
discharge circuit 9 to lower output instruction voltage V3 from the
first voltage value to the second voltage value based on output
current I1 and current threshold It.
Third Exemplary Embodiment
Next, another control method of controller 12 for output
instruction voltage V3 will be described with reference to FIG.
7.
In the first exemplary embodiment or the second exemplary
embodiment, according to an operation in an emergency power supply
mode of on-vehicle power supply device 6, when output power W1
becomes larger than power threshold Wt or output current I1 becomes
larger than current threshold It ("Yes" in step G), controller 12
lowers output instruction voltage V3 to discharge circuit 9 from
the first voltage value to the second voltage value (step H).
On the other hand, in the present exemplary embodiment, when output
current I1 becomes larger than current threshold It in the
emergency power supply mode as illustrated in FIG. 7, controller 12
performs control for causing discharge circuit 9 to sequentially
lower the output instruction voltage continuously or stepwise from
the first voltage value to the second voltage value according to a
value of the output current.
In addition, output current I1 and current threshold It have been
used and described. However, output power W1 and power threshold Wt
may be used instead of output current I1 and current threshold It
for decision in step G similarly to FIG. 3A.
As indicated by a timing chart in FIG. 7, controller 12 performs
control for causing discharge circuit 9 to gradually decrease the
output instruction voltage to the second voltage value at t11 of a
timing at which output current I1 maximizes. Consequently, while
output voltage V4 to be actually detected gradually decreases
substantially in synchronization with output instruction voltage
V3, it is possible to shorten a period in which the output voltage
to be detected becomes close to limit voltage VLo. As a result,
output voltage V4 from discharge circuit 9 becomes higher than
limit voltage VLo. Consequently, discharge circuit 9 can stably
supply a drive voltage to control unit 19 and controller 12.
Fourth Exemplary Embodiment
Next, vehicle 14 on which on-vehicle power supply device 6 is
mounted according to the fourth exemplary embodiment of the present
disclosure will be described with reference to FIG. 8.
A difference between configurations of vehicle 14 illustrated in
FIG. 8 and vehicle 14 illustrated in FIG. 3 is that on-vehicle
power supply device 6 illustrated in FIG. 8 further includes
residual detector 23 which detects a residual electricity storage
amount of electricity storage 7. The other components are the same,
and therefore will be assigned the same reference signs, and
description of the components will be omitted.
Residual detector 23 can detect the residual electricity storage
amount of electricity storage 7, and a detection result is input to
controller 12. Furthermore, controller 12 determines a value of
power threshold Wt based on the residual electricity storage amount
input from residual detector 23.
According to this configuration, when the residual electricity
storage amount of electricity storage 7 lowers, power which can be
supplied from discharge circuit 9 to load 13 also lowers. However,
discharge circuit 9 is controlled by controller 12 to output power
corresponding to the residual electricity storage amount of
electricity storage 7, so that on-vehicle power supply device 6 can
stably supply power.
In the above exemplary embodiments, in a case where controller 12
operates on-vehicle power supply device 6 in an emergency power
supply mode, when output power W1 of output current I1 and output
voltage V4 becomes larger than power threshold Wt, controller 12
performs control for causing discharge circuit 9 to lower output
instruction voltage V3 from the first voltage value to the second
voltage value. In addition, when output current I1 becomes larger
than current threshold It, controller 12 may perform control for
causing discharge circuit 9 to lower output instruction voltage V3
from the first voltage value to the second voltage value.
In addition, a timing at which controller 12 lowers output
instruction voltage V3 in the above exemplary embodiments may be
determined as t1 illustrated in FIG. 4 in association with power
threshold Wt and current threshold It.
In addition, controller 12 may lower output instruction voltage V3,
set an upper limit value to output current I1 and operate
on-vehicle power supply device 6 in the emergency power supply
mode. Naturally, when the upper limit value set to output current
I1 is a value at which an electric motor can start rotating at
above output instruction voltage V3, i.e., a value larger than a
value at which load 13 can operate when load 13 is the electric
motor.
One example will be described by using a specific value. It is
assumed that, in a case where controller 12 operates on-vehicle
power supply device 6 in the emergency power supply mode,
on-vehicle power supply device 6 has capability which can output
power of 200 W at the current of 20 A and the voltage of 10 V when
electricity storage 7 is fully charged. In this regard,
irrespective of whether or not electricity storage 7 is fully
charged, when output power W1 is more than or equal to power
threshold Wt, output power of on-vehicle power supply device 6 is
lowered to 80 W. That is, charge circuit 8 may be controlled by
controller 12 to send an output at the current of 10 A and the
voltage of 8 V. 8 V which is the output voltage may be the output
instruction voltage of controller 12. That is, at a timing of t1 at
which output power W1 illustrated in FIG. 4 is more than or equal
to power threshold Wt, controller 12 lowers output instruction
voltage V3, and controller 12 further suppresses output current I1
to less than or equal to the upper limit value.
Consequently, when controller 12 lowers output instruction voltage
V3, power supplied from electricity storage 7 to discharge circuit
9 is also suppressed. As illustrated in FIG. 1, internal resistance
R is provided inside electricity storage 7. Hence, as power
supplied from electricity storage 7 to discharge circuit 9 lowers,
the current flowing to electricity storage 7 also lowers, and the
voltage drop caused by internal resistance R also inevitably
lowers. As a result, when output power W1 from on-vehicle power
supply device 6 is lowered, loss inside electricity storage 7 also
becomes little. Hence, although the voltage of electricity storage
7 is placed in a situation that the voltage of electricity storage
7 easily fluctuates at a timing of t3 from a timing of t1
illustrated in FIG. 4, the internal loss is suppressed, so that the
voltage and the current supplied from electricity storage 7 and
discharge circuit 9 stabilize.
Naturally, when controller 12 lowers output instruction voltage V3,
output voltage V4 from discharge circuit 9 easily follows output
instruction voltage V3 reliably. Furthermore, output voltage V4 of
discharge circuit 9 easily maintains a higher voltage than limit
voltage VLo.
Irrespective of whether electricity storage 7 is fully charged,
output power W1 is more than or equal to power threshold Wt or
output current I1 is more than or equal to current threshold It,
on-vehicle power supply device 6 suppresses output power W1 or
output current I1 to less than or equal to the upper limit value.
On the other hand, when the residual electricity storage amount of
electricity storage 7 lowers in particular, controller 12 may set
output power W1 according to the residual electricity storage
amount of electricity storage 7, and discharge circuit 9 may be
controlled by controller 12 to output power set according to the
residual electricity storage amount. Consequently, on-vehicle power
supply device 6 can stably supply power with a little fluctuation
in the emergency power supply mode.
Although not illustrated in FIG. 8, power for operating controller
12 is supplied from electricity storage 7 or discharge circuit 9 in
the emergency power supply mode.
In addition, examples of load 13 according to the above exemplary
embodiments include a motor which needs a temporarily large current
during activation. Load 13 is, for example, a motor which operates
to unlock a door, or a motor which operates to unlock a door
latch.
For ease of description related to the above exemplary embodiments,
controller 12 is described as the independent element. The function
of controller 12 may be dispersed and implemented in electricity
storage 7, discharge circuit 9, charge circuit 8, input unit 10 and
output unit 11.
Conclusion
On-vehicle power supply device 6 according to the present
disclosure includes: electricity storage 7; charge circuit 8 which
is provided on a charging route of electricity storage 7, and
charges electricity storage 7 with power; discharge circuit 9 which
is provided on an output route of electricity storage 7, and
discharges the power of electricity storage 7; input unit 10 which
is connected with charge circuit 8; output unit 11 which is
connected with discharge circuit 9; and controller 12 that detects
an input voltage of input unit 10, an output current of output unit
11, and an output voltage of output unit 11, and controls charge
circuit 8 and discharge circuit 9, and, when controller 12 decides
that an emergency operation condition is satisfied, controllers 12
causes the charge circuit 8 to stop charging power to electricity
storage 7, then sets output instruction voltage V3 which is a
target voltage value of an output of discharge circuit 9 to a first
voltage value, controller 12 further causes discharge circuit 9 to
discharges the power charged in electricity storage 7, and, when
the power output from discharge circuit 9 is higher than power
threshold Wt, the controller lowers output instruction voltage V3
from a first voltage value to a second voltage value.
According to on-vehicle power supply device 6 according to the
above present disclosure, when controller 12 detects that the input
voltage has become lower than an input lower limit voltage, the
emergency operation condition may be satisfied.
On-vehicle power supply device 6 according to the present
disclosure of the above present disclosure may further include
collision signal receiver 20 which is connected with controller 12
and receives a collision signal, and, when collision signal
receiver 20 receives the collision signal, the emergency operation
condition may be satisfied.
On-vehicle power supply device 6 according to the above present
disclosure may further increase output instruction voltage V3 from
the second voltage value to the first voltage value when the power
output from discharge circuit 9 becomes higher than power threshold
Wt and then becomes lower than power threshold Wt again.
As described with reference to FIG. 6, on-vehicle power supply
device 6 according to the above present disclosure may compare the
power output from discharge circuit 9 and power threshold Wt by
using a current value.
As described with reference to FIG. 7, according to on-vehicle
power supply device 6 according to the above present disclosure,
when lowering output instruction voltage V3 from the first voltage
value to the second voltage value, controller 12 may lower output
instruction voltage V3 from the first voltage value to the second
voltage value continuously or stepwise.
As described with reference to FIG. 8, on-vehicle power supply
device 6 according to the above present disclosure may further
include residual detector 23 which detects a residual electricity
storage amount of electricity storage 7, and power threshold Wt may
be determined based on the residual electricity storage amount of
electricity storage 7 detected by the residual detector 23.
Furthermore, on-vehicle power supply device 6 according to the
present disclosure includes: electricity storage 7; charge circuit
8 which is provided on a charging route of electricity storage 7,
and charges electricity storage 7 with power; discharge circuit 9
which is provided on an output route of electricity storage 7, and
discharges the power of electricity storage 7; input unit 10 which
is connected with charge circuit 8; output unit 11 which is
connected with discharge circuit 9; and controller 12 that detects
an input voltage of input unit 10, an output current of output unit
11, and an output voltage of output unit 11, and controls charge
circuit 8 and discharge circuit 9, and, when controller 12 decides
that an emergency operation condition is satisfied, charge circuit
8 stops charging of electricity storage 7, then discharge circuit 9
discharges the power at a first voltage, controller 12 further
causes discharge circuit 9 to discharge the power charged in
electricity storage 7, and, when the power output from discharge
circuit 9 becomes higher than power threshold Wt, discharge circuit
9 discharges the power at a second voltage value smaller than the
first voltage value.
Vehicle 14 according to the present disclosure includes: on-vehicle
power supply device 6 according to one of the above; vehicle body
15 on which on-vehicle power supply device 6 is mounted; and
vehicle battery 17 which is mounted on vehicle body 15 and supplies
power to on-vehicle power supply device 6.
According to the present disclosure, the on-vehicle power supply
device lowers the output instruction voltage by a predetermined
value when large output power is necessary in, for example, the
emergency power supply mode in particular. Consequently, temporary
pulsation of an output voltage which occurs as the output power
reaches a supply limit, in other words, temporary pulsation of an
output voltage which occurs due to an influence from the load is
suppressed. Consequently, a significant fluctuation of a output
voltage is alleviated. Consequently, the on-vehicle power supply
device can output a stable voltage without additionally providing
an auxiliary electricity storage element. As a result, the
on-vehicle power supply device can stably operate, and realize
miniaturization at the same time.
INDUSTRIAL APPLICABILITY
The on-vehicle power supply device according to the present
disclosure provides an effect that it is possible to perform a
stable operation and realize miniaturization at the same time, and
is useful for various electronic devices.
REFERENCE MARKS IN THE DRAWINGS
1, 6: on-vehicle power supply device
2, 13: load
3: electricity storage element
4: auxiliary electricity storage element
5: switch unit
7: electricity storage
8: charge circuit
9: discharge circuit
10: input unit
11: output unit
12: controller
14: vehicle
15: vehicle body
16: switch
17: vehicle battery
18: power transmission line
19: control unit
20: collision signal receiver
21: collision detector
23: residual detector
30: output unit
I1: output current
It: current threshold
V1, V3: output instruction voltage
V2, V4: output voltage
VLo: limit voltage
W1: output power
Wt: power threshold
* * * * *